Production of olefines from alkyl borates



Uflitcd States Patent 3,260,769 PRODUCTION OF OLEFINES FROM ALKYL BORATES Dennis Marshall, Norton-on-Tees, England, assignor to Imperial Chemical Industries Limited, London, England, a corporation of Great Britain No Drawing. Filed Sept. 22, 1965, Ser. No. 489,390 Claims priority, application Great Britain, Oct. 6, 1964,

40,723/ 64 V 12 Claims. (Cl. 260682) This invention relates to the production of olefines and in particular to the production of olefines by the decomposition of alkyl borates.

It is known that certain alkyl borates can be decomposed at elevated temperatures and that the decomposition products may contain olefines.

We have now found that this decomposition reaction elevated temperature with a sold catalyst.

A wide variety of catalysts a branched chain alkyl borates in which the alkyl group group, particularly an carbon atoms.

The borate ester is preferably an orthoborate or a metaborate but a borate intermediate in composition between an orthoand meta-borate or a borate having a higher boron content than the metaborate may be cmis a lower alkyl alkyl group containing at most 8 ployed.

process. When the borate 1s decomposed in the vapour phase a very suitable carbon cracking catalyst.

The most satisfactory decomposition temperature depends on the particular alkyl borate to be decomposed. Suitable temperatures are usually within the range 150 to 350 C.

Example 1 Composition of Surface Boiler Distildistillate, mol. Catalyst area, Temp., lation percent nil/gram Texan,

Octenes Octanol-2 Tungstic oxide- 20 172-194 100-108 92 8 Tungstic oxide on titania 40 158-182 78-110 94 6 Tungsten sulphide 150-168 -118 98 2 Iron fluoride on silica alumina 182-208 -110 89 11 -/-A1umina 100 184-226 100-150 69 31 Silica/alumina 230 200-240 126-150 77 23 Thoria 30 204-234 100-134 85 15 Aluminium phosphate 187-204 -116 86 14 Copper chromate 180-236 106-136 81 19 Zinc oxide 202-284 146-210 73 27 Copper oxide/zinc oxide 30 218-244 108-134 63 37 Chromia on alumina 248-300 160-220 53 47 Zinc chromate 244-306 -164 57 43 Example 2 100 grams n-pentyl-l-metaborate were heated at 220 C. to 300 C. with 10 ml. of a silica-alumina cracking catalyst having a surface area of 230 square metres/gram. A distillate was obtained consisting of 60% pentenes and 40% pentanol-l.

C. in the absence of a catalyst some decomposition occurred but most of the metaborate was converted into the more volatile orthoborate which distilled unchanged.

Example 3 N-pentyl-l-orthoborate 325 C. and the residence time of the vapourin contact When the cracking catalyst was replaced by silica chips no decomposition of the ester was observed at a temperature of 450 C. and a residence time of three minutes.

Example 4 1. A process for the production of olefines in which an alkyl or cycloalkyl borate is brought into contact at elevated temperature with a catalyst selected from the group consisting of hydrogenation/dehydrogenation, hydration/dehydration and hydrocarbon cracking catalysts.

2. A process as claimed in claim 1 in which the cata- 3 st has a surface area of at least 5 square metres per 3. A process as claimed in claim 2 in which the catast is selected from the group consisting of tungstic oxide, ingsten sulphide, alumina, alumina/ silica, thoria and luminium phosphate.

4. A process as claimed in claim 2 in which the catalyst selected from the group consisting of tungstic oxide, ungsten sulphide and thoria.

5. A process as claimed in claim 1 in which the alkyl ;roup contains at most 8 carbon atoms.

6. A process as claimed in claim 1 in which the borate s selected from the group consisting of orthoborates and netaborates.

7. A process as claimed in claim 1 in which the borate is in the liquid phase.

8. A process as claimed in claim 1 in which .the borate is in the vapour phase.

9. A process as claimed in claim 8 in which the catalyst comprises alumina/silica.

10. A process as claimed in claim 1 in which the temperature is within the range 150 C. to 350 C.

11. A process for the production of olefines in which an alkyl borate R.B. where R is an alkyl or cycloalkyl group containing at most 8 carbon atoms and B is an orthoborate or metaborate group is brought into contact at a temperature within the range 150 C. to 350 C. with a catalyst selected from the group consisting of hydrogenation/dehydrogenation, hydration/dehydration and hydrocarbon cracking catalysts.

12. A process as claimed in 11 in which the catalyst is selected from the group consisting of ltungstic oxide, tungsten sulphide, alumina, alumina/silica, thoria and aluminium phosphate.

References Cited by the Examiner O DELBERT E. GANTZ, Primary Examiner,

G. E. SCHMITKONS, Assistant Examiner. 

1. A PROCESS FOR THE PRODUCTION OF OLEFINES IN WHICH AN ALKYL OR CYCLOAKLYL BORATE IS BROUGHT INTO CONTACT AT ELEVATED TEMPERATUTE WITH A CATALYST SELECTED FROM THE GROUP CONSISTING OF HYDROGENATION/DEHYDROGENATION, HYDRATION/DEHYDRATION AND HYDROCARBON CRACKING CATALYSTS. 